Wind Power

Chapter 4. Technical Characteristics of Renewable Energy by Source

4.2 Environmental Properties of RE Source

4.2.2 Wind Power

Using a wide-band antenna, Kang Jong-shik (2012) researched the conditions created by electromagnetic waves near solar PV power plants in Korea. The waves were measured inside and outside the inverter room and at the PV modules and the surrounding cattle farms. The largest waves were detected inside the inverter room; however, the level was below the World Health Organization (WHO) guideline of 20%. In 2013, the electromagnetic waves of PV power plants were also measured on bicycle lanes in Sejong Special Self-Governing City by Kang Jong-shik (2012). The measurements show that the electromagnetic waves from the PV power plant were equivalent to 1/500 to 1/1,000 of electrical field (87 V/m) and the magnetic field (62.5 mG), which are the recommended standards to protect human bodies from the effects of electromagnetic waves. This implies that these electromagnetic waves were lower than those emitted by the fans or laptop computers frequently used at home.

4.2.1.3 Harmful Substances of PV Panels

As PV panels include harmful substances, environmental pollution is caused with their breaking down or disposal process. PV modules, like semiconductors, undergo chemical treatment to remove impurities and lacking due attention, it could have a negative impact on the environment, including soil and water.

However, solar PV panels can be recycled at least 80% through the recycling process, and there is no pollution source during the recycling process, which can reduce the impact of environmental damage through solar panel recycling.

In addition, there are concerns over lower harvests caused by a rise in the surrounding temperature, tidal damage owing to the light reflex of the modules, and water pollution caused by cleaning their surfaces.

However, such effects have not been proven objectively.

❙ Table 4-8 ❙ Environmental impact of wind power

Subject Environmental Impact

Atmosphere • Reduction of environmental pollution and global warming by replacing fossil fuel.

• Reduction of ability to lower CO2 if construction destroys vegetation and forests

Nature

• Rotor blades can kill birds and affect their habitats or migration routes.

• The erection of wind power plants inevitably destroys the areas used for their operation facilities, substations, access roads for construction vehicles, cranes, and to secure safety and vision.

• Construction of wind power plants disturbs the landscape and ecosystem.

• Depending on the type of land used for wind power plants, environmental issues, such as damage to vegetation, ecosystem, and habitats can be raised.

Living Environment

• As there is no solid waste, there are no waste disposal issues.

• Wind power plants cause changes in the landscape and put stress on habitats.

• Shadows of pillars of power generators and their rotor blades cause stress for residents nearby.

• Residents nearby could develop wind turbine syndrome (WTS).

• Light reflex from rotor blades of wind power generators affect people or livestock.

Social &

Economic Environment

• The price of electricity is not affected by fossil fuel prices.

• Wind power output is highly dependent on the fluctuation of wind speed and hours of generation, lowering stability of power supply.

• In a country where wind power generation is well established, there are positive social awareness and support from residents.

Source: Kwon et al. (2015)

4.2.2.1 Topographic Damage

Wind power facilities require larger construction areas compared with other energy sources. The Bureau of Land Management of USA (BLM)

estimated

that one generator needs approximately one to three acres, or 4,000 to 12,000 m², of land (Lee Hee-sun et al, 2009). Furthermore, many generators must be installed to ensure economic feasibility. Therefore, a large area is affected and, in addition, during construction, more areas are needed for ramps for construction equipment. In order to install a wind turbine generator, it is necessary to add not only the area required for the power plant construction, but also the additional area for the installation of auxiliary facilities such as an access road and a transmission line to enter the construction equipment, and thus large-scale terrain damage is inevitable

Such topographical damage is likely to have a negative impact on the environment, such as landslide damage (landslide), forest and soil carbon dioxide abatement ability during the rainy season.

❙ Table 4-9 ❙ Threshold value for affecting seascape

Distance Visual Impact

< 13 km Major visual impact

13~24 km General visual impact

> 24 km Minor visual impact

Source: Wratten et al. (2005)

Unlike onshore wind power, offshore wind power is less likely to obstruct natural scenery. However, a view over the sea could be obstructed and spoiled by the offshore wind power district, depending on the distance from the coast, the number of turbines, and the leading light from wind power facility.

4.2.2.2 Ecosystem Destruction

As wind speed rises with altitude, the alpine zone is often appropriate to build onshore wind farms. In Cameroon, a high mountain range is located in the northern region, which, at more than 2,000 m high, could be the most suitable for wind power generation. However, it would be difficult to prevent the destruction of the ecosystem and the magnificent natural landscape, such as the Rhumsiki Valley and the Waza National Park. Moreover, these areas are designated as sanctuaries for wild animals.

❙ Table 4-10 ❙ Leading human-related causes of bird mortality in the US Human-related causes Number of birds kill per year (million)

Cats 1,000

Buildings 100

Hunters 1400

Vehicles 60~80

Communication towers 10~40

Pesticides 67

Wind-power generation facilities could destroy animal habitats, thereby endangering their survival.

Moreover, birds are killed frequently by the rotor blades of the turbines. However, Saidur et al. (2011) have contested the estimates of birds killed from such collisions. These authors contend that the number of birds dying from other causes is significantly higher and that the effect of wind power plants on birds is therefore not a serious environmental issue. According to these authors, the habitat of endangered species could be protected by relocating the animals. Moreover, wind farms could be tourist attractions if they are built in harmony with their surrounding areas.

[Figure 4-25] Noise pattern of wind power generator

Source: Saidur et al. (2011)

The effect of offshore wind power generation on the environment is more diverse compared with that of onshore wind power generation, as it affects the marine environment both under and above the sea. There are floating wind power facilities; however, most offshore wind power facilities are installed at the bottom of the ocean, depriving benthic organisms of their habitat, as piles are driven into the seabed and cables are laid to conduct the electricity to the land. Floating material or soil disturbed during construction can indirectly affect creatures living in the ocean, especially filter-feeders. However, it is difficult to determine

whether such impact is critical to the overall marine ecosystem, except for the ecological environment of the sensitive benthic organisms. Moreover, if the construction is completed quickly, the submarine environment will be less likely affected, except those areas where the facilities are located. However, the noise and vibration associated with the construction process and with the operation after construction must be considered. The German Bundesministeriumfür Umwelt, Naturschutz und Reaktorsicherheit (BMU) measured the noise created during the construction process of wind power facilities in the North Sea and the Baltic Sea. The noise created when the central structure was built in the North Sea reached 193 dB from a place 400 m away, whereas that in the Baltic Sea reached 196 dB from the place 300 m away. According to Gill (2005), the maximum noise level was 260 dB during the foundation phase of construction and 178 dB when the cables were laid underground.

The electromagnetic field and the heat of the power lines inserted into the power system also have effects on the environment. Although the strength of the electromagnetic field varies depending on the capacity of the power line, but an electromagnetic field is always formed around the power line. An HVDC (High Voltage Direct Current) power line, called the Baltic Cable, interconnecting the grids of Germany and Sweden, is a 1,330 ampere line with a maximum transmission power of 600 MW. The magnetic field 6 m away from the line is equivalent is equivalent to the size of the Earth's magnetic field at this point. Such a strong magnetic field could affect the navigation of ship passing on the sea surface directly above the cable, as well as fish and marine organisms who navigate by using the magnetic field of the earth. Sharks (Elasmobranchii), known to be sensitive to magnetic fields, move closer to the magnetic field if they are in the range 0.005~ 1μVcm1 and avoid it beyond 10 μVcm1. Studies have been conducted on marine life for several weeks and on mussels exposed to a magnetic field during the breeding season. The results indicated that the magnetic field, specifically from power lines, did not have a particular effect on the ecology or physiology of benthic organisms. However, there are not so many studies with definite conclusions on the possibility of long-term accumulated effects, or whether marine organisms could be affected by magnetic fields while searching for food or during seasonal migration.

4.2.2.3 Noise and Vibration

Wind power generation causes problems of noise and low frequency noise, due to wind turbines, to neighboring residents. The noise caused by the wind turbine can be divided into mechanical noise and aerodynamic noise.The former is made by transmission, power generation devices, and journal bearings

However, the low frequency apparently affects people, as a significant number of residents in the US and Japan complained of suffering WTS, with symptoms such as heart disease, migraine, dizziness, tinnitus (ringing in ears), and sleep disorders.

As regards offshore wind power, if it is assumed that atmospheric noise is not conducted by sea water. A wind power generator with 1 MW capacity generates noise up to approximately 103 dB, which could

reach up to

106 dB for multiple generators.³⁴ Thomsen et al. (2006) measured the noise from a single turbine with 1.5 MW capacities in Utgruden (Sweden) from a location 110 m away from the turbine. At an average wind speed of 12 m/s, the noise level was approximately 90 to 115 dB.

[Figure 4-26] Regions affected by shadow flicker of wind power generators over time

Source: Kwon Young-Han et al. (2011); Gilead Power Corporation (2008)

In addition, wind power generation causes shadow flicker, which is the shadow flickering effect caused by the sunlight creating shadows when the wing is rotating. This could affect the wellbeing of neighboring residents.